Joint Fluid Analysis

Arthrocentesis is the aseptic technique for aspiration of fluid from a joint.

Crystals:
- Calcium pyrophosphate (pseudogout)
  - Positive birefringence
  - Rhomboid shaped, Yellow crystals
- Calcium urate (Gout)
  - Negative birefringence
  - Needle shaped crystals, Blue crystals
Gram stain
- Positive in <25% gonococcal infections
- Positive in 50-75% non-gonococcal

: Joint Effusion Analysis Table

About Mike Cadogan

Emergency physician with a passion for medical informatics and medical education. Founder of GMEP and HealthEngine. Asynchronous learning and #FOAMed evangelist | @sandnsurf | + Mike Cadogan | Contact